Steven M. Kurtz PhD, Genymphas B.Higgs PhD, EdmundLau MS, Richard R.Iorio MD, P. MaxwellCourtney MD, JavadParvizi MD

The Journal of Arthroplasty, 2021, ISSN 0883-5403
doi: 10.1016/j.arth.2021.10.018

Summary by Emanuele Chisari MD

The standard of care for chronic PJI in the United States is two-stage revision surgery. Following the first stage, also named resection, the patient should receive antibiotic treatment and then wait for reimplantation in about 6 to 12 weeks from the original surgery. However, this does not always happen. Attrition between the two stages is often associated with increased morbidity and mortality and many previous studies[1]–[4] have examined the risks, treatments, outcomes, and economics associated with 2-stage treatment. It is clear from previous research that infected total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) are more economically costly than aseptic revisions, even when the strategy is successful [5]–[7]. However, assessing the cost of surgical procedures is not an easy task and has been discussed multiple times in the literature pertinent to PJI.

In this study, the authors focused on analyzing the inpatient economic burden of 2-stage hip and knee revisions for PJI by considering the hospitalization costs during 4 phases of the treatment strategy: (1) first-stage surgery involving resection of the infected TJR and placement of the spacer; (2) interstage period between the explantation and staged reimplantation surgeries; (3) second-stage surgery involving spacer removal and reimplantation with a permanent revision implant; and (4) post-reimplantation period. To do so, they analyzed Medicare data from publicly available databases.

A total of 5,094 total hip arthroplasty and 13,062 total knee arthroplasty patients had an index revision for PJI during the study period. In the first 12 months following the first-stage explantation, the likelihood of completing a second-stage PJI revision was 43.1% (95% confidence interval [CI] 41.7-44.5) for hips and 47.9% (95% CI 47.0-48.8) for knees. Following explantation, 1-year patient survival rates for hip and knee patients were 87.4% (95% CI 85.8-88.9) and 91.4% (95% CI 90.6-92.2), respectively. The median additional cost for hospitalizations between stages was $23,582 and $20,965 per patient for hips and knees, respectively. Hospital volume, Northeast or Midwest region, and younger age were associated with reduced PJI costs (P < .05).

The analysis of Medicare data has limitations. As the database is constructed primarily for reimbursement of medical claims, many clinically relevant patient factors for the treatment of infection, such as success on eradicating the infection, are not captured. However, the capability to use some hospital-based cost-to-charge ratios rather than direct costs potentially decreased source of bias even though they cannot be generalized across hospitals.

Overall, the authors report that the gold standard 2-stage revision strategy for PJI had less than a 50% chance of completing the planned 2-stage surgery among patients over 65 years of age. This outcome was also found to be associated with increased cost and healthcare utilization.

References

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